Technology developed for the ultimate dry and dusty environment could provide a major boon for the nascent solar-energy industry in the Middle East.

The region has one of the highest levels of solar radiation in the world, making it an ideal location for solar PV plants. However, a big problem is the equally high dust-deposition rate, which has a dramatic impact on the efficiency of solar panels.

“A dust layer of one-seventh of an ounce per square yard decreases solar power conversion by 40%,” says Malay K. Mazumder from Boston University in the US. “In Arizona, dust is deposited each month at about four times that amount. Deposition rates are even higher in the Middle East, Australia, and India.”

Self-cleaning PV systems are available, but these traditionally rely on water, which is a valuable resource in the Middle East. Now the latest research is looking into using an electric charge produced by the panels themselves in order to clean them.

The technology involves placing a transparent, electrically-sensitive material deposited on glass, or a transparent plastic sheet covering the panels. Sensors monitor dust levels on the surface of the panel, and energise the material when dust concentration reaches a critical level.

The electric charge sends a dust-repelling wave cascading over the surface of the material, lifting away the dust and transporting it off of the screen’s edges. Within two minutes, the process removes about 90% of the dust deposited on the panels. It requires only a small amount of electricity generated by the panel for cleaning purposes.

The need for such technology is growing with the popularity of solar energy. Use of PV panels increased by 50% from 2003 to 2008, and forecasts suggest a growth rate of at least 25% annually into the future.

“Our technology can be used in both small- and large-scale PV systems. To our knowledge, this is the only technology for automatic dust cleaning that does not require water or mechanical movement.”

Working with NASA, Mazumder and colleagues initially developed the self-cleaning PV panel technology for use in lunar and Mars missions. “Mars, of course, is a dusty and dry environment, and solar panels powering rovers and future manned and robotic missions must not succumb to dust deposition. Neither should solar panels here on Earth.”

The current market for PV panels is about US$24 billion, according to Mazumder. “Less than 0.04% of global energy production is derived from solar panels, but if only 4% of the world’s deserts were dedicated to solar-power harvesting, our energy needs could be completely met worldwide. This self-cleaning technology can play an important role.”